Chefs at last night’s Waitrose Summer Party at the Natural History Museum were underwhelmed by the 5:2 diet, in which you eat almost nothing for two days a week and feast on the other five. “It’s ridiculous,” said French chef Raymond Blanc. “The British are so messed up about food. They have fear and guilt, they binge and purge. Why can’t they just enjoy food? There’s no food culture here, like in France, although it’s growing.”